Input detection device and method for manufacturing input detection device

ABSTRACT

According to an aspect, an input detection device includes: a first substrate; a second substrate disposed to face the first substrate, the second substrate including a main surface having an area smaller than an area of a main surface of the first substrate; and a height difference portion disposed above the first substrate. An electrode layer is disposed on the main surface of the second substrate opposite to the first substrate and on a side surface of the second substrate constituting the height difference portion.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No.15/346,066, filed Nov. 8, 2016, which claims priority from JapaneseApplication No. 2015-228162, filed on Nov. 20, 2015, and JapaneseApplication No. 2016-216245, filed on Nov. 4, 2016, the contents ofwhich are incorporated by reference herein in its entirety.

BACKGROUND

1. Technical Field

The present invention relates to an input detection device capable ofdetecting an external proximity object and a method for manufacturingthe input detection device.

2. Description of the Related Art

Input detection devices capable of detecting an external proximityobject, or so-called touch panels have recently been attractingattention. A display device with a touch detection function that is adisplay device on which a touch panel is stacked is generally known. Asfor a small device such as a mobile phone and a tablet, the reduction indevice thickness and the simplification of the manufacturing process areespecially required.

As a technique for thinning the device and simplifying the manufacturingprocess, for example, it can be considered that a touch detectionelectrode is directly formed on the counter substrate of the liquidcrystal cell filled with liquid crystals. This configuration saves thespace for another substrate for a touch panel and also saves time andeffort to provide the substrate.

However, the device described above requires flexible substrates onwhich, for example, various control circuits and a power source areinstalled on both the pixel substrate and the counter substrate. Thereis a problem that the two or more flexible substrates physicallyinterfere with each other or need space in the device.

In consideration of the above, Japanese Patent Application Laid-openPublication No. 2014-120003 (JP-A-2014-120003) discloses a technique ofusing conductive paste to couple a detection electrode on the countersubstrate to a terminal on the pixel substrate.

JP-A-2014-120003 further discloses as an embodiment that the end surfaceof the height difference portion of the counter substrate is obliquelyscribed.

In the above-described technique, improvement in coupling stabilitybetween an electrode on the counter substrate and a terminal on thepixel substrate has been desired.

For the foregoing reasons, there is a need for an input detection devicethat is excellent in coupling stability between the electrode on thecounter substrate and a terminal on another substrate.

SUMMARY

According to an aspect, an input detection device includes: a firstsubstrate; a second substrate disposed to face the first substrate, thesecond substrate including a main surface having an area smaller than anarea of a main surface of the first substrate; and a height differenceportion disposed above the first substrate. An electrode layer isdisposed on the main surface of the second substrate at an opposite sideto the first substrate, and on a side surface of the second substrateconstituting the height difference portion.

According to another aspect, a method for manufacturing an inputdetection device includes the steps of: sticking a first substrate and asecond substrate together with a sealing member; and forming anelectrode layer on a main surface and a side surface of the secondsubstrate.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating an exemplary configuration of an inputdetection device according to an embodiment of the present invention;

FIG. 2 is a diagram illustrating a state in which a conductor such as afinger and a support is not in contact with or close to an input device;

FIG. 3 is a diagram illustrating a state in which a conductor is incontact with or close to the input device;

FIG. 4 is a schematic diagram for explaining the principle ofdetermining proximity or contact of the object in accordance with adetection signal of the input detection device;

FIG. 5 is a cross-sectional view of the main parts of the inputdetection device according to the present embodiment;

FIG. 6 is a diagram illustrating an exemplary configuration of the inputdetection device according to the present embodiment;

FIG. 7 is a plan view of the input detection device according to thepresent embodiment;

FIG. 8 is a cross-sectional view of a coupling structure of wiring foran input detection electrode according to the present embodiment;

FIG. 9 is a diagram illustrating a modification of the presentembodiment;

FIG. 10 is a diagram illustrating a comparative example;

FIG. 11 is a diagram illustrating a second modification of the presentembodiment;

FIG. 12 is a diagram illustrating another example of routing wires usingconductive paste;

FIG. 13 is a diagram illustrating an exemplary coupling structure usingthe conductive paste;

FIG. 14 is a diagram illustrating exemplary dimensions of a heightdifference portion of a counter substrate having an inclined surface;

FIGS. 15A to 15F are explanatory diagrams each illustrating a generaloutline of a manufacturing method according to the present embodiment;

FIGS. 16A and 16B are perspective views of the input detection deviceafter a conductive body is formed in the input detection device; and

FIG. 17 is an enlarged view of the height difference portion.

DETAILED DESCRIPTION

Modes (embodiments) for carrying out the present invention will bedescribed below in detail with reference to the drawings. The contentsdescribed in the embodiments are not intended to limit the presentinvention. Components described below include components easilyconceivable by those skilled in the art and components substantiallyidentical therewith. Furthermore, the components described below can beappropriately combined. The disclosure is given by way of example only,and various changes made without departing from the spirit of theinvention and easily conceivable by those skilled in the art naturallyfall within the scope of the invention. The drawings may possiblyillustrate the width, the thickness, the shape, and other elements ofeach unit more schematically than the actual aspect to simplify theexplanation. These elements, however, are given by way of example onlyand are not intended to limit interpretation of the invention. In thespecification and the figures, components similar to those previouslydescribed with reference to a preceding figure are denoted by likereference numerals, and overlapping explanation thereof will beappropriately omitted.

1-1. Overall Configuration

FIG. 1 is a diagram illustrating an exemplary configuration of an inputdetection device according to an embodiment of the present invention.

An input detection device 1 includes: a display device 10 with an inputdetection function including an input detection device 30 and a displaydevice 20; a gate driver 12; a source driver 13; a drive electrodedriver 14; a control unit 11 that controls the drivers; and a touchdetection unit 40.

In the present configuration, some components of the input detectiondevice 30 and the display device 20 are shared. The present embodimenthas an in-cell structure in which the common electrode is used as acommon electrode for display and a drive electrode for detecting input.

The control unit 11 operates the gate driver 12, the source driver 13,the drive electrode driver 14, and the touch detection unit 40 insynchronization with one another.

During a video display period in which a video is displayed, inaccordance with a video signal Vdisp transmitted from the outside to thecontrol unit 11, a scanning signal Vscan is sequentially provided fromthe gate driver 12 to the selected horizontal lines. Meanwhile, a pixelsignal VPix is provided to each selected pixel from the source driver13, and a drive signal Vcom for display is provided from the driveelectrode driver 14 to the drive electrode (common electrode) COML.

During an input detection period in which input is detected, a drivesignal Vcom for detecting input is provided from the drive electrodedriver 14 to the drive electrode COML. Meanwhile, the touch detectionunit 40 outputs a detection signal from an input detection electrode TDLincluded in the input detection device 30 (see FIG. 5).

Examples of the touch detection unit 40 include, but are not limited to,a signal amplifier 42, an A/D converter 43, a signal processing unit 44,a coordinate extraction unit 45, a noise detection unit 46, and adetection timing control unit 47.

The control unit 11 can perform, for example, noise correction inaccordance with a detection result from the touch detection unit 40 asnecessary.

In the present embodiment, the input detection device can employ notonly the in-cell structure described above, but also an on-cellstructure in which both the detection electrode and the drive electrodeare provided on the counter substrate, and a self-capacitance on-cellstructure in which input is detected only by the detection electrodedisposed on the counter substrate.

1-2. Touch Detection Principle

An aspect of the touch detection principle according to the presentembodiment will be described below.

The present embodiment employs the principle of capacitive touchdetection.

FIG. 2 is a diagram illustrating a state in which a conductor such as afinger and a support is not in contact with or close to the inputdevice. FIG. 3 is a diagram illustrating a state in which a conductor isin contact with or close to the input device.

As illustrated in FIG. 2, a capacitance element C1 is formed between apair of electrodes E1 and E2 facing each other. The electrodes E1 and E2hold a dielectric body D therebetween and are electrically separate fromeach other.

The electrode E1 is used as a drive electrode to which a drive signalfor detecting a touch is applied, and a drive signal Sg (Vcom that isapplied to the common electrode during a touch period in the presentembodiment) is applied to the electrode E1. Meanwhile, the electrode E2is grounded as a detection electrode via a resistor and coupled to thetouch detection unit 40.

When an alternating-current signal at a predetermined frequency issupplied as a drive signal Sg to the electrode E1 in a state where afinger is not in contact with the electrode E2, a current correspondingto the capacitance of the capacitance element C1 illustrated in FIG. 2flows in accordance with the charge and discharge of the capacitanceelement C1, and the electrode E2 outputs a predetermined detectionsignal (Vdet in FIG. 4) in accordance with the value of the flowingcurrent.

On the other hand, when a finger is in contact with the electrode E2, acapacitance element C2 generated by the finger is added to thecapacitance element C1 in series. Thus, when the drive signal Sg issupplied to the electrode E1, a current corresponding to the capacitanceelement C1 and the capacitance element C2 flows from the electrode E2.The value of the current is lower than the value of the currentcorresponding to only the capacitance element C1. Thus, the voltagevalue of the detection signal Vdet detected from the electrode E2 islower than the voltage value of the detection signal Vdet when thefinger is not in contact with the electrode E2.

FIG. 4 is a schematic diagram for explaining the principle ofdetermining proximity or contact of an object in accordance with thedetection signal of the input detection device. As illustrated in FIG.4, the voltage value of the detection signal Vdet when a finger is notin contact with the electrode E2 is V₀, and the voltage value of thedetection signal Vdet when a finger is in contact with the electrode E2is V₁. By distinguishing between the voltage values in accordance withan arbitrary threshold Vth, it is determined whether a finger is incontact with the electrode E2.

The principle of the input detection device of a mutual-capacitancetechnology has been described in the present embodiment. However, theprinciple of detection by a self-capacitance technology can be employedin the present embodiment. In the self-capacitance technology, the drivesignal Sg is applied to the electrode E2. Then, the electrode E2 isdecoupled from the source of the drive signal, and coupled to thedetection unit so that a detection waveform Vdet including thevariations in capacitance of the electrode E2 is output. In such a case,input can be detected only by a touch detection electrode layer.

The principle of detection by the input detection device of the presentembodiment is not limited to the principles described above. Anotherprinciple of detection can be employed.

1-3. Exemplary Configuration of Input Detection Device

FIG. 5 is a cross-sectional view of the main parts of the inputdetection device according to the present embodiment. FIG. 6 is adiagram illustrating an exemplary configuration of the input detectiondevice according to the present embodiment.

The display device 10 with an input detection function includes a pixelsubstrate 21 as a first substrate, a counter substrate 31 as a secondsubstrate facing the pixel substrate 21, and a liquid crystal layer 4filled with liquid crystals and interposed between the pixel substrate21 and the counter substrate 31.

Common electrodes COML and pixel electrodes 22 arranged in a matrix areformed on the surface of the pixel substrate 21. Wires such as pixelsignal lines that transmit a pixel signal VPix to the respective pixelelectrodes 22, and scanning signal lines that drive thin filmtransistors provided on the respective pixels, are also formed on thepixel substrate 21. Wires that provide a drive signal to the respectivecommon electrodes COML are also formed.

Input detection electrodes TDL that detects contact or proximity of anobject (conductor) F such as a finger, and a color filter 32 are formedon the counter substrate 31.

In the present embodiment, as illustrated in FIG. 6, the driveelectrodes (common electrodes) COML and the input detection electrodesTDL are patterned in a stripe-shape and arranged facing each other suchthat capacitance is formed in crossing portions in which the driveelectrodes (common electrodes) COML three-dimensionally cross therespective input detection electrodes TDL.

The shapes of the drive electrodes (common electrodes) COML and theinput detection electrodes TDL are not limited to stripes and can beformed in an arbitrary pattern.

A dummy electrode or a guard electrode can be arranged in the same layeras that of the input detection electrode TDL. For example, any one offloating potential, ground potential, and an alternating-current signalin synchronization with the drive electrode can be applied to the dummyelectrode and the guard electrode. For example, an opening can bearbitrarily provided on the input detection electrode TDL.

For example, the pattern shapes or materials disclosed in JapanesePatent Application Laid-open Publication No. 2014-191660 and JapanesePatent Application Laid-open Publication No. 2014-191650 can be used asthe pattern shape or material of the input detection electrodes TDLaccording to the present embodiment. Alternatively, another publiclyknown electrode pattern or material can be used.

Each of the input detection electrodes TDL is coupled via a wire to thetouch detection unit 40. When the drive signals Vcom are supplied to therespective common electrodes COML arranged in a scanning direction SC onthe pixel substrate 21 during the touch period, the input detectionelectrodes TDL output the detection signals Vdet to the touch detectionunit 40 in response to the supply of the drive signal Vcom.

1-4. Coupling Structure of Wires for Obtaining Detection Signal fromInput Detection Electrodes

FIG. 7 is a plan view of the input detection device according to thepresent embodiment. Examples of an electronic component 5 illustrated inFIG. 7 include, but not are limited to, at least one of the gate driver12, the source driver 13, and the drive electrode driver 14 illustratedin FIG. 1. The electronic component 5 is provided on the pixel substrate21 by the chip on glass (COG) technology. The electronic component 5 iscontrolled in accordance with the control signal from the control unit11 illustrated in FIG. 1.

In the present embodiment, as illustrated in FIG. 7, the input detectionelectrodes TDL included in the display device 10 with an input detectionfunction are formed in a region overlapping with a display region AA ona main surface 31 a of the counter substrate 31 in a planar view. In aframe region positioned outside of the display region AA, electrodes areformed in the same layer as that of the input detection electrodes TDL,and are electrically coupled to the input detection electrodes TDL. Theelectrodes in the frame region are formed in the same layer as that ofthe input detection electrodes TDL until the side surface at the end ofthe counter substrate 31 where the counter substrate 31 and the pixelsubstrate 21 constitute a height difference portion 8. An electrodelayer 71 formed in the frame region and on the side surface of thecounter substrate 31 can function as wiring of the input detectionelectrodes TDL formed in the display region AA. The electrode pattern inthe frame region or on the side surface of the counter substrate 31 isnarrower in width than the electrode pattern in the display region AA.In the height difference portion 8, a conductive body 50 is formed onthe input detection electrodes TDL formed on the side surface of thecounter substrate 31. The conductive body 50 electrically couples theinput detection electrodes TDL to a terminal group 7 on the pixelsubstrate 21. In the present embodiment, the conductive body 50 isconductive paste, for example, made of a resin composition including aconductive substance such as silver. The terminal group 7 iselectrically coupled to a flexible printed circuit (FPC) substrate 6coupled to the pixel substrate 21.

Various circuits that control, for example, the control circuit on thepixel substrate 21 are mounted on the FPC substrate 6. The touchdetection unit 40 is mounted on the FPC substrate 6 so that the touchdetection unit 40 is directly coupled to the input detection electrodesTDL. Thus, the control of the display operation and the control of theinput detection operation can be performed in the single FPC substrate6. This configuration can thin and downsize the device.

FIG. 8 is a cross-sectional view of the coupling structure of wiring forthe input detection electrodes according to the present embodiment. Asillustrated in FIG. 7, the area of the main surface 31 a of the countersubstrate 31 is smaller than the area of a main surface 21 a of thepixel substrate 21 so that the main surface 31 a does not overlap withthe electronic component 5 on the pixel substrate 21. As illustrated inFIG. 8, the height difference portion 8 is formed at the portionoverlapping with the pixel substrate 21 at the end of the countersubstrate 31 in a planar view.

The height difference portion 8 is disposed above the pixel substrate21, and is constituted of a plurality of elements having differentheights in a height direction perpendicular to the main surface 21 a ofthe pixel substrate 21, the elements including a portion of the mainsurface 21 a of the pixel substrate 21, the conductive body 50 disposedon the pixel substrate 21, and the input detection electrodes TDL formedon the main surface 31 a of the counter substrate 31. The heightdifference portion 8 includes the side surface of the counter substrate31. On the side surface of the counter substrate 31 where the heightdifference portion 8 is positioned, the electrodes are provided in thesame layer as that of the input detection electrodes TDL formed on themain surface 31 a of the counter substrate 31.

Furthermore, the conductive body 50 is disposed on the electrodes formedon the side surface so that the conductive body 50 electrically couplesthe electrodes to the terminal group 7 formed on the pixel substrate 21.The drive electrodes (common electrodes) (not illustrated) are disposed,for example, on the pixel substrate 21. The drive electrodes may bestacked on the pixel electrodes or may be formed in the same layer asthat of the pixel electrodes. The drive electrodes may be formed on thecounter substrate 31.

In the present embodiment, the electrodes in the same layer as that ofthe input detection electrodes TDL are formed on the side surface of thecounter substrate 31. This configuration decreases the distance betweenthe input detection electrodes TDL and the terminal group 7 formed onthe pixel substrate 21. This configuration can suppress thedisconnection of the conductive body 50 when the input detectionelectrodes TDL and the terminal group 7 are coupled via the conductivebody 50.

FIG. 9 is a diagram illustrating a modification of the presentembodiment. In the modification, at least a part of the side surface ofthe counter substrate 31 has an inclined surface in the heightdifference portion. In other words, the side surface of the countersubstrate 31 includes an inclined surface 85 and a vertical surface 86without an inclination. The vertical surface includes the side surfaceof the counter substrate 31 and a sealing member 9.

Furthermore, the inclined surface 85 includes a curved surface.

The electrodes included in the same layer as that of the electrodesdisposed on the main surface 31 a of the counter substrate 31 aredisposed at least at a part of the inclined surface 85 in the presentmodification. The conductive body 50 is formed on the electrodesdisposed at least on the inclined surface 85 so that the conductive body50 electrically couples the electrodes to the terminal group 7.

In the present modification, the side surface at the end of the countersubstrate constituting the height difference portion 8 includes theinclined surface 85, which decreases the thickness of the countersubstrate 31 toward the outside. Thus, the conductive body 50 can beformed along the inclined surface 85. This configuration improves thestability of coupling between the electrodes and the conductive body 50on the inclined surface 85. The side surface of the counter substrate 31includes the inclined surface 85. This configuration can facilitateforming electrodes on the side surface of the counter substrate 31 andin the same layer as that of the main surface 31 a of the countersubstrate 31. This also improves the stability of coupling of theelectrodes and the counter substrate 31.

It is preferable in the present embodiment that the electrodes formed onthe side surface of the counter substrate 31 are formed in the sameprocess as that of forming the input detection electrodes TDL on themain surface 31 a of the counter substrate 31, and the electrodes on themain surface 31 a and the side surface of the counter substrate 31 aremade of the same material and are formed continuously.

It is preferable in the present embodiment that the electrodes formed onthe side surface of the counter substrate 31 are formed in the sameprocess as that of forming the input detection electrodes TDL on themain surface 31 a of the counter substrate 31, and the electrodes on themain surface 31 a and the side surface of the counter substrate 31 havesubstantially the same thickness.

Liquid crystals are filled between the pixel substrate 21 and thecounter substrate 31, and sealed with the sealing member 9.

The display function layer provided between the pixel substrate 21 andthe counter substrate 31 is not limited to the liquid crystal layer 4,and may be an organic EL layer.

In such a case, another material may be arbitrarily employed as amaterial corresponding to the sealing member 9.

The conductive body 50 only needs to be formed at least on the sidesurface at the end of the counter substrate 31, and is not necessarilyformed on the main surface 31 a of the counter substrate 31. Thus, thethickness of the input detection device does not increase due to thethickness of the conductive body 50.

The conductive body 50 may be formed also on the main surface 31 a ofthe counter substrate 31 as necessary.

FIG. 10 is a diagram of a comparative example.

In FIG. 10, the input detection electrodes TDL or the wires included inthe same layer as that of the input detection electrodes TDL are formedonly on the main surface 31 a of the counter substrate 31. In order toelectrically couple the input detection electrodes to the pixelsubstrate 21, it is necessary to form conductive paste on the mainsurface 31 a of the counter substrate 31.

In such a coupling structure, the distance between the electrode layer71 and the pixel substrate 21 is long. Thus, it is necessary todischarge a large amount of a conductive body in order to electricallycouple the electrode layer 71 to the pixel substrate 21. This may causeelectric short circuit or disconnection, which deteriorates thestability of coupling.

FIG. 11 is a diagram illustrating a second modification of the presentembodiment. In the second modification, a height difference absorptionlayer 91 is provided outside the sealing member in the height differenceportion 8, and thus the conductive body 50 is formed to have a portioninclined from the counter substrate 31 toward the pixel substrate 21,and having a predetermined angle with respect to the pixel substrate 21.The predetermined angle is lower than 90°. Alternatively, the conductivebody 50 may be formed to have the inclined portion having thepredetermined angle by making the sealing member 9 protrude from thecounter substrate 31.

When there is a gap between the pixel substrate 21 and the sealingmember 9, there is a possibility of the conductive paste entering intothe gap by capillary action depending on the compositions or viscosityof the conductive paste. Providing the height difference absorptionlayer 91 as described above can solve such a problem.

FIG. 12 is a diagram illustrating another example of routing the wiresusing conductive paste. A way to route the wires with conductive pastemay be such that the wires of all the input detection electrodes TDL aregathered in one place. Alternatively, for example, the wires may bedivided and routed into two places to avoid the electronic component 5(COG) as illustrated in FIG. 12. Alternatively, another way to route thewires can be employed.

The inclined surface of the side surface at the end of the countersubstrate 31 according to the present embodiment is formed only in theplace where the wires are routed with the conductive paste. It isunnecessary to form the inclined surface in a place where the wires arenot routed.

In the present embodiment, the inclined surface 85 can be formed only ina desired region because the inclined surface 85 of the countersubstrate 31 is formed with a new manufacturing method as describedbelow.

FIG. 13 is a diagram illustrating an exemplary coupling structure of theconductive paste.

In FIG. 13, an electrode included in the same layer as that of a singleinput detection electrode TDL is disposed on the inclined surface 85.

Forming the electrode at the steepest part in the center of the inclinedsurface 85 makes it easy to route the wiring using the conductive pasteon the pixel substrate 21 by using gravity and the inclined surface 85when the conductive paste is discharged from above the part. Thisconfiguration reduces, for example, the short circuit, and improves thestability of coupling between the electrode and the conductive paste.

Various coupling structures using the conductive paste other than thestructure described above can be employed. FIG. 14 is a diagramillustrating exemplary dimensions of the height difference portion 8 ofthe counter substrate 31 including the inclined surface 85. A distance Afrom the position where the inclined surface 85 is formed on the mainsurface 31 a of the counter substrate 31 to the end of the countersubstrate 31 is preferably within a range from 50 μm to 1 mm.

A thickness B of the thickest part of the counter substrate 31 ispreferably within the range from 50 μm to 1 mm. A thickness C of thethinnest part is preferably within the range from 5 μm to 30 μm. Thelonger the distance A is, the better the stability of coupling among theelectrode, the conductive body 50, and a terminal of the terminal group7 is. However, too long distance A may increase the frame region of theinput detection device 1.

The thinner the thickness C is, the better the stability of couplingamong the electrode, the conductive body 50, and a terminal of theterminal group 7 is. However, the thickness C can be appropriatelyadjusted in consideration of a manufacturing limit and the durability ofthe substrate.

The material of the input detection electrodes TDL of the presentembodiment is not specifically limited, but electrodes containing metalwith a light-shielding property are used in the present embodiment.

Even when the metal-containing electrode is constituted of fine lines ina mesh pattern, for example, the electrode can be electrically coupledacross the height difference without disconnection in the presentembodiment.

1-5. Method for Manufacturing Input Detection Device

Hereinafter, a method for manufacturing the input detection device 1according to the present embodiment will be described.

The method for manufacturing the input detection device 1 according tothe present embodiment includes a process for sticking the firstsubstrate and the second substrate together with the sealing member 9,and a process for forming the electrode layers 71 on the main surface 31a and the side surface of the second substrate.

One of the features of the input detection device 1 according to thepresent embodiment is that when the electrode layers 71 are formed asinput detection electrodes TDL on the main surface 31 a of the secondsubstrate, the electrode layers 71 are also formed on the side surfaceof the second substrate. The electrode layers 71 formed on the mainsurface 31 a and on the side surface of the second substrate arepreferably in the same layer.

Furthermore, the conductive body 50 that electrically couples theelectrode layers 71 to the terminal group 7 disposed on the firstsubstrate is formed on the electrode layers 71 formed on the sidesurface of the second substrate.

A spattering method can be employed as an exemplary method for formingelectrodes on the side surface of the substrate.

As described above, the conductive body 50 is formed on the electrodeson the side surface of the second substrate. This configuration improvesthe stability of coupling among the electrode layers 71, the conductivebody 50, and the terminal group 7.

The method for manufacturing the input detection device 1 according tothe present embodiment is described in greater detail below. The methodincludes the following processes (a) to (e).

(a) A process for sticking the first substrate and the second substratetogether with the sealing member 9;

(b) a process for forming a first concave portion 81 on the surface ofthe second substrate;

(c) a process for forming a second concave portion 82 on the secondsubstrate by etching the second substrate including the first concaveportion 81, the second concave portion 82 being the etched first concaveportion 81;

(d) a process for forming the electrode layer 71 on the surface of thesecond substrate including the second concave portion 82; and

(e) a process for forming a cut surface 89 and an inclined surface 85including a part of the second concave portion 82 by cutting the secondsubstrate in the direction perpendicular to the second substrate along aline including the second concave portion 82.

Hereinafter, each of the processes will be described in detail.

Process (a)

In the present process, the first substrate that is the pixel substrate21 and the second substrate that is the counter substrate 31 are stucktogether with the sealing member 9. A display function layer such as theliquid crystal layer 4 is disposed between the first substrate and thesecond substrate. The liquid crystals of the liquid crystal layer 4 maybe dropped before the sticking or may be injected after the sticking.

In the present embodiment, the first substrate is the pixel substrate21, and the second substrate is the counter substrate 31. Alternatively,the first substrate and the second substrate may be another substratesuch as a protective substrate.

The display function layer that is sealed between the substrates is notlimited to the liquid crystal layer 4, and may be an arbitrary displayfunction layer such as an organic EL layer.

Process (b)

In the present process, the first concave portion 81 is formed on thesurface of the counter substrate 31 that is the second substrate.

Laser irradiation is preferably used as a method for forming the firstconcave portion 81.

Alternatively, for example, a scriber may be used to mechanically formthe first concave portion 81.

At this time, the size or the depth of the first concave portion 81 canbe controlled in the present process so that the counter substrate 31with a desired thickness and the second concave portion 82 with adesired size are finally formed.

The first concave portion 81 may be formed only in a position where theinclined surface 85 is to be formed, or may be formed entirely on oneside of the substrate along the height difference portion 8.

At least one or more first concave portions 81 are formed. A pluralityof first concave portions 81 may be formed.

Process (c)

In the present process, the counter substrate 31 on which the firstconcave portion 81 is formed is etched. A wet etching method ispreferable for the etching.

The counter substrate 31 made of glass is chemically etched with etchingliquid. This etching thins the thickness of the counter substrate 31 andthree-dimensionally and evenly sharpens the first concave portion 81formed in the previous process. Then, the second concave portion 82larger than the first concave portion 81 is formed on the surface of thecounter substrate 31. The second concave portion 82 is etched into ahemispherical concave portion having a spherical surface inside.

At this time, the etching is controlled to prevent the second concaveportion 82 from penetrating and puncturing the counter substrate 31.

At this time, a plurality of stacked second concave portions 82 may formthe inclined surface 85.

In this process, the second concave portion 82 having a curved surfaceis uniformly formed. Meanwhile, even if the laser irradiation in theprevious process develops a crack on the substrate, the etching processremoves the crack. Thus, the counter substrate 31 with higher durabilitycan be formed without developing a crack, in comparison with a methodfor mechanically cutting the substrate with a scriber, for example, toform an inclined surface.

When the first concave portion 81 is formed and foreign materials suchas glass substances are scattered in the process (b), the etchingprocess can remove the foreign materials. Thus, the conductivity of theelectrode layer 71 is not reduced when the electrode layer 71 is formedin the next process.

The inclined surface 85 formed by the second concave portion 82 formedas described above can be controlled to become a predetermined inclinedsurface 85 that enhances the coupling reliability of the electrodes. Theabove-described control can be performed, for example, by controllingthe size and depth of the initial concave portion formed in the process(b) and adjusting the etching conditions.

Process (d)

In the present process, the electrode layer 71 is formed on the countersubstrate 31.

At this time, the electrode layer 71 is also formed on the surface ofthe second concave portion 82 in the same layer as that of the electrodelayer 71 on the counter substrate 31. The electrode layer 71 can beformed in an arbitrary method such as evaporation and spattering.

The electrode layer 71 is patterned as necessary. The electrode layer 71overlapping with the display region can be used as the input detectionelectrode TDL and the electrode layer 71 disposed in the frame regionand on the inclined surface 85 of the second substrate can be used asoutput wiring of the input detection electrodes TDL.

Process (e)

In the present process, the second substrate is cut in the directionperpendicular to the substrate along a line including the second concaveportion 82 so that the cut surface 89, and the inclined surface 85including a part of the second concave portion 82 are formed.

In this process, the height difference portion 8 is constituted by thecut surface 89, the inclined surface 85, the first substrate, and thesecond substrate.

The cut surface 89 includes at least the counter substrate 31. The cutsurface according to the present embodiment further includes the sealingmember 9.

The inclined surface 85 is a surface formed by cutting the secondconcave portion 82.

At this time, the counter substrate 31 is preferably cut such that thedeepest part of the second concave portion 82 formed on the countersubstrate 31 is aligned with the above-described line.

Alternatively, the counter substrate 31 may be cut at a position outsidethe deepest part of the second concave portion 82, and wiring may beprovided such that the conductive body 50 is embedded in the deepestpart.

Conductive Body Forming Process (f)

In addition to the processes described above, the conductive body 50 canbe formed by performing the process of forming the conductive body 50 soas to extend over at least the cut surface 89, the inclined surface 85,and a part of the surface of the first substrate.

At this time, the conductive body 50 is formed on the input detectionelectrode formed on the inclined surface 85.

A conductive body may be also formed on the main surface 31 a of thecounter substrate 31.

However, in the present embodiment, because the coupling stability ofthe electrodes is high, a conductive body is not necessarily formed onthe main surface 31 a of the counter substrate 31. In this case, thethickness of the conductive body can be eliminated.

FIGS. 15A to 15F are explanatory diagrams each illustrating a generaloutline of the manufacturing method according to the present embodiment.FIGS. 16A and 16B are perspective views of the input detection deviceafter the conductive body is formed. FIG. 17 is an enlarged view of theheight difference portion.

As illustrated in FIG. 17, a height difference is formed such that apart 88 of the second concave portion 82 is left at the end of the cutcounter substrate 31.

As illustrated in FIG. 16A, the second concave portions 82 may be formedsuch that the entire side surface at the end of the counter substrate 31does not form the inclined surface 85, and the inclined surface 85 isformed only in an arbitrary portion. As illustrated in FIG. 16B, thesecond concave portions 82 may be continuously formed such that theentire side surface forms the inclined surface 85.

The configuration of the second concave portions 82 can be controlled byadjusting the conditions of forming the first concave portion 81 and theetching conditions.

For example, a conductive liquid composition or a conductive viscouscomposition is discharged with a dispenser or the like, to form theconductive body 50.

For example, conductive paste such as silver paste can be employed asthe conductive body 50.

The conductive paste discharged on the inclined surface 85 flows ontothe pixel substrate 21 by gravity. This can reduce the short circuit ofthe wires using the paste.

At this time, the viscosity of the conductive paste can be adjusted asappropriate.

Wires using the conductive paste can be directly routed, for example, toa terminal on the FPC substrate coupled to the pixel substrate 21.However, another wire may be separately formed between the conductivepaste and the terminal to couple them to each other.

According to the disclosure of the present embodiment as describedabove, it is possible to provide an input device that includes a smallnumber of components, is thinned, is downsized, is excellent in design,and exhibits excellent performance for input detection. Furthermore, itis also possible to provide an input device that causes less cracks, hasless foreign materials, and is excellent in durability and stability atthe time of manufacturing.

In the input detection device of the present embodiment, because theelectrode layer is also formed on the side surface of the secondsubstrate constituting the height difference portion, the inputdetection device is excellent in coupling stability when the electrodeon the second substrate is electrically coupled to the first substratefacing the second substrate.

Application of the present disclosure includes electronic apparatus suchas various input devices, mobile phones, tablets, personal computers,digital cameras, televisions, and wearable devices including anelectronic wristwatch.

The preferred embodiments of the present invention have been describedabove. However, the present invention is not limited to the embodiments.The contents disclosed in the embodiments are merely examples. Theembodiments can be variously modified without departing from the gist ofthe present invention. The present invention naturally encompassesappropriate modifications maintaining the gist of the invention.

What is claimed is:
 1. A method for manufacturing an input detectiondevice, the method comprising the steps of: (a) sticking a firstsubstrate and a second substrate together with a sealing member; (b)forming a first concave portion on a surface of the second substrate;(c) forming a second concave portion on the second substrate by etchingthe second substrate including the first concave portion, the secondconcave portion being the etched first concave portion; (d) forming anelectrode layer on the surface of the second substrate including thesecond concave portion; and (e) forming a cut surface and an inclinedsurface including a part of the second concave portion on a side surfaceof the second substrate by cutting the second substrate in a directionperpendicular to the second substrate along a line including the secondconcave portion.
 2. The method for manufacturing an input detectiondevice according to claim 1, the method further comprising the step offorming a conductive body on the electrode layer formed on the inclinedsurface on the side surface of the second substrate, the conductive bodyelectrically coupling the electrode layer to a terminal group arrangedon the first substrate.
 3. The method for manufacturing an inputdetection device according to claim 1, wherein the first concave portionis formed by laser irradiation in step (b).
 4. The method formanufacturing an input detection device according to claim 1, whereinthe etching in step (c) uses a wet etching method.
 5. The method formanufacturing an input detection device according to claim 1, whereinthe second concave portion formed in step (c) is larger than the firstconcave portion formed in step (b).
 6. The method for manufacturing aninput detection device according to claim 2, wherein the conductive bodyis formed by discharging a conductive liquid composition or a conductiveviscous composition.
 7. The method for manufacturing an input detectiondevice according to claim 1, wherein the second substrate is cut at adeepest part of the second concave portion formed on the secondsubstrate in step (e).
 8. The method for manufacturing an inputdetection device according to claim 1, wherein the etching is performedin step (c) such that the second concave portion formed on the secondsubstrate does not penetrate the second substrate in a thicknessdirection of the second concave portion.